SQL Trigger chaining IF statements - mysql

Question

I seem to be unable to have multiple, non-related if statements in SQL
I have a table of users with a bunch of columns that should be unique, but some are also optional. Since SQL throws an error when more than one fields have a NULL value, I decided to approach the problem with a trigger.
Here is how I wrote it:
create definer = root#localhost trigger `check-if-unique-update`
before UPDATE
on contact
for each row
if new.phone2 is null
then
if (select count(id) from contact where phone2 = new.phone2 or phone = new.phone2) > 0
then
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'There is something wrong with the Contact data you entered!';
end if;
end if;
if new.email2 is not null
then
if (select count(id) from contact where email2 = new.email2 or email = new.email2)
then
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'There is something wrong with the Contact data you entered!';
end if;
end if;
if new.fax is not null
then
end if;
end if;
First off, DataGrip (DataBase management IDE by JetBrains) gives me an error. When I then upload the file to the MySql DataBase it only shows the first if Statement
if new.phone2 is null
then
if (select count(id) from contact where phone2 = new.phone2 or phone = new.phone2) > 0
then
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'There is something wrong with the Contact data you entered!';
end if;
end if;
I feel like I am missing some rudimentary detail, or is this just not possible in sql?

Answer 1

Have you tried including a begin-end in your trigger?
create definer = root#localhost trigger `check-if-unique-update`
before UPDATE
on contact
for each row
begin
if new.phone2 is null
then
if (select count(id) from contact where phone2 = new.phone2 or phone = new.phone2) > 0
then
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'There is something wrong with the Contact data you entered!';
end if;
end if;
if new.email2 is not null
then
if (select count(id) from contact where email2 = new.email2 or email = new.email2)
then
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'There is something wrong with the Contact data you entered!';
end if;
end if;
if new.fax is not null
then
end if;
end if;
end
Depending on your IDE, you may need to change the delimiter to // for example.
For reference see: https://dev.mysql.com/doc/refman/8.0/en/trigger-syntax.html